6x6 post

I have a 6x6 post that goes from the ground to the roof and on the top half it supports a balcony but the post goes from the roof to the ground and about 8 ft of the post from the ground is rotted. how can i support the post so it wont sag and i can cut about 8 ft long piece out and then add another post from the ground up about 8 ft. The entire post is about 20 ft long. any sugestions on how to support it so i can cut 8 ft off on the bottom half and add a new piece. please help thank you

6x6 post

There are ways to splice into a post, but then it would need lateral support. I think that anything 20' long would need some lateral support anyhow. An 8' 6x6 is quite heavy, I hate to think what a 20' one weighs. But the only I know of to temporarily support that is with another 20' post. That being the case, just replace it all. You will likely need a crane anyhow.